Hi, I am exploring the history of contributions using the OSM history dump (see wiki Planet.osm/full). Looking at the provided data, I found 24707 changesets in which there were no edits.

Someone has an idea about what happened with these datasets?

asked 28 Oct '14, 18:54

jfd553's gravatar image

jfd553
2208917
accept rate: 0%

edited 28 Oct '14, 23:33

aseerel4c26's gravatar image

aseerel4c26 ♦
28.6k14215490


The API 0.6 method 'create changeset' allows you to create a changeset without doing any subsequent additions to that changeset. Reason might be anything from broken uploads (e.g. network issues), editor bugs, etc..

I even remember one case where a mapper created a huge number of such empty changesets to make hostile vandalism activities a bit more difficult to deal with. Yes, strange things happen some time, but all that got sorted out fairly quickly.

Update: as Simon provided some editor specific insights, I thought I could add some statistics from by local DB. It's about half a year old, but you should get a rough impression, which editors created how many empty changesets (if they identify themselves by name). You could of course group the entries by editor type (ignoring different editor versions, languages) - this is left as an exercise to the reader.

                                  created_by                                   |   c   
-------------------------------------------------------------------------------+-------
                                                                               | 50761
 Potlatch 0.11b                                                                | 46702
 Potlatch 1.4 (live en)                                                        | 42190
 Potlatch 1.0                                                                  | 39909
 Potlatch 2                                                                    | 38173
 Potlatch 0.11                                                                 | 35890
 Potlatch 1.4 (live de)                                                        | 31094
 Potlatch 1.2                                                                  | 24265
 Go Map!! 1.1                                                                  | 22264
 Potlatch 1.1a                                                                 | 16447
 Potlatch 1.2a                                                                 | 15092
 Potlatch 0.11a                                                                | 14166
 Potlatch 1.2b                                                                 | 11621
 ArcGIS Editor for OpenStreetMap (2.0)                                         | 11466
 Potlatch 1.2c (live)                                                          |  9622
 osmitter 0.1                                                                  |  9548
 Potlatch 1.3e (live en)                                                       |  9079
 JOSM                                                                          |  7920
 Potlatch 1.4 (live ru)                                                        |  7848
 Potlatch 1.4 (live fr)                                                        |  7273
 iD 1.3.7                                                                      |  7147
 iD 1.3.4                                                                      |  6990

Statement:

select created_by,count(*) c from changes where num_changes = 0 group by created_by order by c desc;

Tool used to populate the Postgres database was https://github.com/zhm/osmchanges-postgres Give it a try, it's not terribly difficult to set up and run this query.

permanent link

answered 28 Oct '14, 21:17

mmd's gravatar image

mmd
5.5k4987
accept rate: 37%

edited 30 Oct '14, 18:35

1

see https://www.openstreetmap.org/user/SimonPoole/diary/23352 note that the editor GoMap!, at least in the version available up to a short time ago, created an empty changeset as method of checking if the authentication worked.

(30 Oct '14, 07:51) SimonPoole ♦

In the case of "Go Map!" at credentials-checking changesets are identifiable as such:

http://www.openstreetmap.org/changeset/16640349

Though it can create others:

http://www.openstreetmap.org/changeset/21804635

I also see quite a lot of empty changesets from other editors:

http://www.openstreetmap.org/changeset/26183795

http://www.openstreetmap.org/changeset/25568455

http://www.openstreetmap.org/changeset/24536371

but not id?

My apologies to the authors of all of the changesets above - you're not being singled out for any other reason than you happened to use a particular OSM editor!

(30 Oct '14, 09:19) SomeoneElse ♦
(30 Oct '14, 11:52) SomeoneElse ♦
4

I pointed it out in my blog post, it is probably helpful to think of a changeset as setting a "start* marker ..... uploading something ... setting a "stop" marker. If something goes wrong in the upload bit, for example a conflict or a crash or ... the changeset will autoclose after an hour and, hey presto, you have an empty changeset.

Given that opening the changeset is a seperate API operation and there is no way to cancel or otherwise undo it once you have opened one, empty changesets are not completely avoidable.

(30 Oct '14, 12:28) SimonPoole ♦
Your answer
toggle preview

Follow this question

By Email:

Once you sign in you will be able to subscribe for any updates here

By RSS:

Answers

Answers and Comments

Markdown Basics

  • *italic* or _italic_
  • **bold** or __bold__
  • link:[text](http://url.com/ "title")
  • image?![alt text](/path/img.jpg "title")
  • numbered list: 1. Foo 2. Bar
  • to add a line break simply add two spaces to where you would like the new line to be.
  • basic HTML tags are also supported

Question tags:

×91
×71
×33
×6

question asked: 28 Oct '14, 18:54

question was seen: 1,567 times

last updated: 30 Oct '14, 18:35

powered by OSQA